The usefulness of obtaining current real time information from the bottom of a well during drilling is well known within the drilling industry. Data of this type can significantly increase drilling safety, increase drilling efficiency up to 15% and provide accurate real time determinations of hole direction.
Despite the fact that mud pulse telemetry was originally conceived for all of these purposes, the present high cost of providing the service (estimated at $2,500 to $4,500 per day) has limited its usefulness to transmitting hole direction measurements only. One of the most significant factors keeping operating costs high is the general unavailability of high speed, reliable, inexpensive pulser valves. Prior art valves produced pulse rates on the order of one pulse every few seconds, therefore severely limiting the amount of data that can be transmitted at any given time and increasing the cost per data point. Several of the above noted co-pending applications disclose fluidic pulsing devices which are capable of much more rapid transmission of information. Those devices, along with the apparatus disclosed in the present application, represent a significant advancement in the art of mud pulse telemetry.
Another problem with existing systems is the high cost of equipment, estimated to be in the hundreds of thousands of dollars range per system. Still another problem is the relatively great amount of electrical power that is consumed in the bore hole by presently known systems, necessitating the use of auxiliary turbine generators to supply the power.
The art of mud pulse telemetry is in need of a fast acting valve which will permit the reliable transmission of reasonable quantities of data in a short period of time. It is highly desireable that such a valve be an inexpensive device as it may sometimes be left abandoned at the bottom of a well when a break occurs in the drill string. Any such valve must operate efficiently to eliminate the additional costs required for supplying significant amounts of auxiliary power.
It is therefore an object of this invention to provide a mud pulse transmitter having a high pulse rate capability.
It is another object of this invention to provide a mud pulse transmitter which is inexpensive to fabricate and to maintain.
It is another object of this invention to provide a mud pulser which is highly reliable in extended periods of operation.
It is still another object of this invention to provide a pulse transmitter which is readily adaptable for use with standard drilling hardware.
Yet another object of this invention is to provide a pulser which requires minimal electrical or other power to operate.